I have a large list, over 5000 items (~6000). I need to enable cascade delete on a lookup column SharePoint errors out and tells me the action exceeds the list view threshold. Note: This feature is working on a list with over 5000 items when I configured the column for cascade delete BEFORE it reached 5000 items.
Has anyone encountered this issue and found some kind of work around to get this enabled?
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I did not find a workaround. I had to use REST to move items out of the list into a new list, make the column index change, then move the items back. We had to also update any lookups to the as the "move" required that items in the original list be deleted.